The objective of the proposed research is to gather new information on the functional interaction between pairs of retinal ganglion and dorsal lateral geniculate cells in order to develop a prototype model on the cellular level of the dLGN. Electrophysiological experiments will be conducted on rats which have been surgically prepared to allow simultaneous microelectrode recording from the retina and dLGN. Based on classification with respect to retinal ganglion cell, dLGN P-cell, dLGN I-cell, ON-center, OFF-center, X type, Y type, overlapping centers and nonoverlapping centers, there are 70 possible pairwise combinations. The functional interactions between these simultaneously recorded pairs of cells will be inferred from the observed statistical dependencies revealed by crosscorrelation analysis. A quantitative model will be developed and tested on these findings and other existing anatomical and functional information.